The economic optimum mob size at lambing for triplet-bearing Maternal and Merino ewes across southern Australia

John Young; Paul Kenyon; Lyndon Kubeil; Andrew Thompson; Jason Trompf; Amy Lockwood

Just Accepted

This article has been peer reviewed and accepted for publication. It is in production and has not been edited, so may differ from the final published form.

The economic optimum mob size at lambing for triplet-bearing Maternal and Merino ewes across southern Australia

John Young , Paul Kenyon, Lyndon Kubeil, Andrew Thompson , Jason Trompf, Amy Lockwood

Abstract

Context: Lambing triplet bearing ewes in smaller mobs significantly increases lamb survival. Aims: This paper reports economic analysis to assess the optimum mob size for triplet-bearing ewes during lambing. Methods: The analyses considered scenarios for Merino and non-Merino (Maternal) flocks where producers subdivided lambing paddocks using permanent fencing or where ewes were reallocated within existing paddocks based on pregnancy status. Key results: The optimum mob sizes for triplet-bearing ewes during lambing were affected by ewe breed, stocking rate, lamb price and the target return-on-investment if subdividing paddocks. The optimum mob size for triplet-bearing Maternal and Merino ewes was between 27% and 40% of the optimum for twin-bearing ewes and this was similar for scenarios where paddocks were subdivided, or where ewes were reallocated within existing paddocks. At the standard lamb price of $7/kg carcass weight, the economic return from adjusting the relative mob size of triplet-bearing ewes was $2.05 per multiple-bearing or $14.20 per triplet-bearing Maternal ewe and $0.54 per multiple-bearing ewe or $5.70 per triplet-bearing Merino ewe. Conclusions: Overall, these analyses demonstrate that reducing mob size at lambing can be a profitable strategy for improving survival of triplet-born lambs depending on the current size of lambing mobs. Implications: As reported previously for single- and twin-bearing ewes, it is difficult to provide generic recommendations to producers for the optimum mob size of triplet-bearing ewes at lambing because optimum mob size was dependent on several enterprise-specific factors.

AN24334 Accepted 23 December 2024